True heterodyne spectrally controlled interferometry
AssigneeApre Instruments, LLC
InventorARTUR OLSZAK
Life of this patent
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Abstract
Heterodyne spectrally controlled interferometry is performed by combining a delay line in Twyman-Green configuration with a Fizeau interferometer. By splitting a white-light beam in the delay line and introducing a time delay in one of the resulting beams, the delay line produces a recombined output beam with a sinusoidally modulated spectrum. By introducing a frequency shift in one of the beams in the delay line, the output beam is also continuously phase shifted in the spectral domain in a time-varying fashion, as required for heterodyne SCI.
Claims16
A method of producing heterodyne interferometric measurement signals for spectrally controlled interferometry:
- providing a light source emitting a white light;
- producing two beams from the white light emitted by said source;
- introducing a frequency shift in one of said two beams;
- spectrally modulating a combination of said two beams to produce a heterodyne beam with a varying spectral distribution;
- and
- injecting said heterodyne beam into an interferometer.
A source of heterodyne light for spectrally controlled interferometry comprising:
- a spectrally controllable light source;
- means for splitting light emitted by said spectrally controllable light source into two beams;
- means for introducing a frequency shift in one of said two beams;
- and
- means for recombining said two beams to produce a heterodyne wavefront.
An interferometric system for spectrally controlled heterodyne interferometry comprising:
- a white-light source;
- a delay line in Twyman-Green configuration optically coupled to the white-light source;
- an acousto-optic modulator adapted to introduce a frequency shift in a beam traveling in an arm of the delay line;
- and
- a Fizeau interferometer adapted to receive a heterodyne beam with a varying spectral distribution emitted by the delay line.
Dependencies are inferred from the claim text.